The objective of the proposed research is to uderstand the metabolic processes governing the breakdown of collagen under normal physiological conditions in the uterus, cervix and Graafian follicle. Breakdown must be regulated with extreme precision to maintain full mechanical function during periods of rapid remodeling. Proteolytic enzymes that digest collagen, gelatin and small synthetic peptides of collagen (DNP-peptides and PZ-peptide) will be purified and characterized. Most of the enzymes of interest are metalloproteases, found in latent forms. The regulatory controls such as mechanisms of activation of the latent enzymes, the levels of tissue inhibitors of metal metalloproteases, hormonal effects on enzyme levels, and the crosslinking of the substrate collagen will be examined in the involuting rat uterus. A serine protease that degrades proteoglycan and a second protease that digests fibrillar collagen, but not tropocollagen, are found to rise abruptly just before dilatation of the rat cervix. These enzymes will be characterized and their role in dilatation will be explored. The changes in the physical state and the degree of crosslinking of cervical collagen and elastin will be followed together with the changes in mechanical properties. The human cervix contains high levels of collagenase and this enzyme appears to spill over into the blood. It could provide a marker for incipient labor. Collagenase and its inhibitors will be measured to see if they account for the process of follicle wall breakdown in ovulation. The findings will be of importance in understanding the role of connective tissue matrix breakdown in uterine involution, cervical dilatation and follicle rupture. This work has broad implications for understanding embryo morphogenesis, skeletal remodeling, regeneration and various pathological processes such as arthritis, cancer invasion, and wound healing. Particular attention will be given to detecting changes in human serum that reflect cervical changes. This could aid in detecting and blocking premature labor in its earliest stages.